In-vivo bleeding may occur due to different diseases in the body. Bleeding in the gastrointestinal (GI) tract may occur in various locations along the GI tract which may indicate different pathologies present at those locations. For example, bleeding in the esophagus may be due to esophagitis or due to ruptures in varices in the esophagus. An ulcer in the stomach, as well as an ulcer in the duodenum, may cause bleeding. And in the lower digestive tract, colorectal cancer may cause occult bleeding. Therefore, early detection of bleeding along the GI tract may be crucial for better treatment of many patients.
There are some known methods in detecting blood, such as using an endoscope to search for bleeding areas, which usually look for acute bleeding. Other methods may involve the use of dye or radioactive material swallowed by a patient such that the dye highlights blood vessels which are then imaged to detect bleeding. Another device which may be used is a device by NOVINEON HEALTHCARE TECHNOLOGY PARTNERS, GMBH, which may be fixed to the inner wall of a hollow organ and may provide continuous monitoring of bleedings. The device emits light having a predetermined wavelength and being at least partially absorbed or reflected in the interior of the hollow organ, and the device then detects the reflected light via a photosensitive sensor. Since blood has a characteristic absorption spectrum that differs from the absorption spectrum of the “normal” organ contents, it can be determined due to the detected reflections whether or not there is any blood inside the hollow organ.
However, this device doesn't take into consideration the presence of bile. Bile that is found in the small bowel may have transmission spectra that is similar to the transmission spectra of blood, such that there may be some inaccuracies regarding the determination of the presence of blood in-vivo. For example, if the transmission spectrum of bile is similar to the transmission spectra of blood, the device may give an indication as to the presence of blood, while there was actually bile present in the examined area. It is important to determine that the transmission spectra indicate the presence of blood and not the presence of bile.